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/*
* Copyright (C) 2001-2008 Jacek Sieka, arnetheduck on gmail point com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#if !defined(BIT_INPUT_STREAM_H)
#define BIT_INPUT_STREAM_H
#include "Exception.h"
namespace dcpp {
STANDARD_EXCEPTION(BitStreamException);
/**
* A clumsy bit streamer, assumes that there's enough data to complete the operations.
* No, doesn't operate on streams...=)
*/
class BitInputStream
{
public:
BitInputStream(const uint8_t* aStream, size_t aStart, size_t aEnd) : bitPos(aStart*8), endPos(aEnd*8), is(aStream) { }
~BitInputStream() { }
bool get() throw(BitStreamException) {
if(bitPos > endPos) {
throw BitStreamException(_("Request to seek beyond the end of data"));
}
bool ret = (((uint8_t)is[bitPos>>3]) >> (bitPos&0x07)) & 0x01;
bitPos++;
return ret;
}
void skipToByte() {
if(bitPos%8 != 0)
bitPos = (bitPos & (~7)) + 8;
}
void skip(int n) {
bitPos += n * 8;
return ;
}
private:
BitInputStream(const BitInputStream&);
BitInputStream& operator=(const BitInputStream&);
size_t bitPos;
size_t endPos;
const uint8_t* is;
};
} // namespace dcpp
#endif // !defined(BIT_INPUT_STREAM_H)
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